Abstract | INTRODUCTION: METHODS: Male Wistar rats with MI or sham-operated controls were treated with either losartan or vehicle. Bromodeoxyuridine ( BrdU) was given to identify newly formed cardiac cells. Immunohistochemical analysis was used to quantify proliferative and apoptotic cardiomyocytes, vascular structures and c-Kit+ stem/progenitor cells, western blotting to evaluate gene expression, and planimetry and echocardiography to assess cardiac structure and function. RESULTS: The number of BrdU+ cardiomyocytes increased similarly in the vehicle and losartan treated MI groups. The number of apoptotic or proliferating cardiomyocytes did not differ between losartan and vehicle treated rats. Losartan induced an increase in capillary and BrdU+ vascular densities in the infarct border zone. Losartan treatment completely prevented post-MI cardiac hypertrophy. In the non-infarcted myocardium the amount of all BrdU+ cells (including non-cardiomyocyte cells) was highest in the vehicle treated MI rats at week 4. CONCLUSIONS: The number of newly formed cardiomyocytes increased after MI. Angiotensin II blockade neither stimulated nor prevented cardiomyocyte regeneration. ARB treatment increased vascular densities in the infarct border zone and modulated remodelling of the non-infarcted myocardium preventing effectively post-MI cardiac hypertrophy.
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Authors | Heli Segersvärd, Päivi Lakkisto, Hanna Forsten, Katariina Immonen, Riikka Kosonen, Eeva Palojoki, Esko Kankuri, Ari Harjula, Mika Laine, Ilkka Tikkanen |
Journal | Journal of the renin-angiotensin-aldosterone system : JRAAS
(J Renin Angiotensin Aldosterone Syst)
Vol. 16
Issue 1
Pg. 92-102
(Mar 2015)
ISSN: 1752-8976 [Electronic] England |
PMID | 23629679
(Publication Type: Journal Article, Research Support, Non-U.S. Gov't)
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Copyright | © The Author(s) 2013. |
Chemical References |
- Angiotensin II Type 2 Receptor Blockers
- Antimetabolites
- Vascular Endothelial Growth Factor A
- Proto-Oncogene Proteins c-kit
- Renin
- Bromodeoxyuridine
- Losartan
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Topics |
- Angiotensin II Type 2 Receptor Blockers
(pharmacology)
- Animals
- Antimetabolites
(pharmacology)
- Apoptosis
(drug effects)
- Body Weight
- Bromodeoxyuridine
(pharmacology)
- Cardiomegaly
(etiology, prevention & control)
- Losartan
(pharmacology)
- Myocardial Infarction
(diagnostic imaging, drug therapy, pathology)
- Myocytes, Cardiac
(drug effects)
- Neovascularization, Physiologic
(drug effects)
- Proto-Oncogene Proteins c-kit
(metabolism)
- Rats
- Regeneration
(drug effects)
- Renin
(blood)
- Stem Cells
- Ultrasonography
- Vascular Endothelial Growth Factor A
(biosynthesis)
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